Method for refining animal and vegetable oils



1 8 1941- B. CLAYTON 2,254,101

METHOD FOR REFINING ANIMAL AND VEGETABLE OILS Filed NOV. 22, 1937 w 2 irrrrrrrrrr r 36 7 rrrrrrrrrrrrrrrrrrr as [/v vE/V TOR BEMJA M/N CLA YTONHARRIS) K/Ech', .FosrsR & HARR 6 'A'TTORNEYJ Patented Aug. 26, 1941METHOD FOR REFINING ANIMAL AND i VEGETABLE OILS Benjamin Clayton,Houston, Tex., assignor to Refining, Ina,

Reno, Nevada Application November 22, 1937, Serial No. 175,971 i (01.260-425) 15 Claims.

This invention relates to a process and apparatus for purifying animaland vegetable oils, including the fish oils and including the fats andgreases commonly classified under the general term of animal andvegetable oils. It particularly relates to a system, preferablycontinuous, for refining such animal and vegetable oils to removevarious impurities and otherwise condition the oil for various uses. Itwill be de- Nev., a u corporation of precipitated and removed prior tothe addition of the alkaline reagent, such as caustic soda, potash,etc., or has been allowed to remain unmodified inthe crude oil until thealkaline reagent has been added so as tobe acted'upon-by this.reagent-and appear in the resulting'soap stock. Ifthe' oil i'streatedtov precipitate and remove the mucilaginous matter before neutralization of the free fatty acids, the'process is often made undulyexpensive andirieificient, for the two separatingysteps necessarilyinvolved each have a tendency to entrain oil with the matter separated,thus resulting in increased refining scribed, in detail with reference.to the alkali refining of glyceride oils, particularly cottonseed oil,as an example. I

Most of the animal and vegetable oils -'con-' tain various materials,herein termed "impurilosses. ties, which it is desired to remove. Thesemay Specifically with. reference to a glyceride-type be of a fatty ornon-fatty character, or both, and are removed by a process hereindesignated.

than those which may beassociated with the By the term micilagi-'mucilaginous matter. nous matter as herein used, I have reference tothose materials known to exist in such oils and variously designated inthefart, among which are gums, resins, phosphatides, mucines; certaincarbohydrates and like impuritiesfas well .as color impurities which maybe associated therewith. some animal and vegetable oils will containmuoil such as cottonseed oil, the mucilaginous matter is probablycolloidally dispersed in-the crude oil and is' not soluble in oil orwater. If it is allowed to remain in the oil .without modifica- 2 tier;and if, as is customary, an excess of alkaline refining reagentisutilized, tests indicate.

that the action is in the following sequence: The first actionwhich-takes place is a neutralization of the fatty acids,almost'instantaneous, forming particles ofisoap stoc which float in itheoil. When the fattyacids ,are neutralized,

-a large portion of the excess alkaline refining reag nt is-absorbed bythemucilaginous matter and {hat is. left acts upon the color impurities.

0 That'portion of the alkaline refining reagent, whic is absorbedby the.mucilaginous matter underoes little or no reaction. However, thismucilaginous matter, with its associated alkaline cilaginous matterfalling within only'one ortwo of the above terms, while'pthersmaycontain a larger number ofthese impurities herein clas'si- F refiningreagent, is capable 'of gathering and ag f ponifying neutral oil untilthe reagent has ipar' 1 tially or wholly become neutralized. This refied as mucilaginous matter. Cottonseed oil, for example,"commonlycontains mucilaginous mat+ ter in the form of vegetable resins, a fewcarbohydrates. and phospho lipins, better known as phosphatides. inaddition to the fatty acids and color'impurities not associated with themucilaginousmatter.

In common practice,- such impurities in animal In refining any suchoils, it is important to reduce to a minimum the refining loss resultingfrom action by the refining reagent on the;

sults in; the production of additional'soape'like I qmaterials whichappear. in the soap stockwhen:

and vegetable oils have been removed by. use oil itself or throughentrainment of oil in the of a refining reagent, usually an alkalinereagent separated foots. In the refining of glycerideif the fatty acidsare to be removed, though type oils, this loss is made up partly of aloss sometimes of an acidic character if the refining, of'neutral 011'due to saponification during" the is not to involve neutra ization. Theterm"r eprocess and'partly'to neutral oil occluded in and fining reagentis used herein as directed. to any separated. with the soap stock. It is'an object rea ent capable of acting upon impurities tube; of thepresent invention to provide an improved removed to form foots which.can be separated process for refining animal and vegetable oils by fromthe oil. which the-refining loss is reduced.

In prior. knowledge in the field of alkali re- It has now beenascertained that veryadvanfining, the mucilaginous matter has. eitherbeen 7 tageous results-can be obtained by adding to the oil, beforeincorporation oi the refining reagent,

attempt to separate the impregnated mucilag'i nous matter, after whichthe foots are separated from the resulting oil. This aqueous medium maybe of such character as to render the mucilaginous matter repulsive tothe subsequently added refining reagent, thereby decreasing the refiningloss due to the refining reagent which would otherwise be absorbed bythe mucilaginous r'natter and thereby act upon the oil itself.

By such pre-treatment with an aqueous medium, it has been found that abetter separation is obtained and that less oil is occluded in theseparated foots. The superior separation is very noticeable when acentrifuge is used as the separating expedient. In such a centrifuge,the feats are thrown outward in the rotating bowl due to centrifugalforce and the aqueous medium is, to some extent, squeezed out and tendsto form an outer layer of liquid which facilitates continuous upwardmovement of the foots near this wall. Such a layer will permit the footsto move easily and uniformly upward and will retard the adherence ofcertain constituents of the foots to the wall of the bowl. Prior to thetime that this action takes place, any excess of the aqueous mediumtends to dilute the foots and, being of greater density than theparticles of foots, tends later to increase the effectiveness ofcentrifugal separation.

Such improved separation will be found to take place even if the amountof aqueous medium added is insufiicient or just sumcient tobe-completely taken up or imbibed by the mucilaginous matter. However,in some instances and with treatment of certain oils, it has been founddesirable to introduce an excess of this aqueous medium over and abovethe amount which will be taken up by the mucilaginous matter. When anexcess of the aqueous medium is added, the excess is immediatelyavailable to dilute, and

the oil. At the same time, the diluted refining.

reagent is surprisingly effective in reducing the color to the desireddegree.

Such an excess of the aqueous medium may be desirable during centrifugalseparation in that it further dilutes the foots and facilitatesformation of the layer adjacent the outer wall bounding the zone ofcentrifugal separation.

It is an object of the present invention to add to a vegetable or animaloil, before addition of a refining reagent, an aqueous mediumfacilitating the process in one or more of the ways mentioned above, theamount of the aqueous medium being either less than, equal to, orgreater than that amount which will be taken up by the mucilaginousmatter.

It is a further object of the invention to reduce the refining loss andfacilitate separation by continuous or batch-operating. means by addinga suitable aqueous medium to the oil before incorporation of therefining reagent.

It is a further object of the invention to provide a novel apparatus forrefining oils.

Further objects and advantages of the invention will be made evident tothose skilled in the art from the following description of On a mode ofperforming the process as exemplified 1 by the alkali refining ofglyceride-type oil.

The drawing diagrammatically illustrates one apparatus by which theinvention can be performed, though it will be clear that the method isnot limited to such an apparatus. It is believed, however, that thisapparatus is novel, as well as the process herein-disclosed.

The glyceride-type oil and an aqueous medium may be respectivelycontained in tanks [0 and II and may be heated therein, if desired, bythe heating coils shown, or may be heated during flow through heaters l2and I3, which may be of the tube or coil type. Proportioned quantitiesof the oil and aqueous medium are brought together and mixed by anysuitable means. For instance, a pump [5 may continuously withdraw oilfrom the tank 10, through the heater I2 if desired, and discharge sameat elevated pressure through a pipe I6 into a mixing means l8.Similarly, a stream of the aqueous medium may be withdrawn from the tankll, through the heater l3 if desired, by a pump 20 and delivered tothemixer [8 through a pipe 2|. Any suitable type of mixing means can beutilized relying upon mechanical agitation or turbulence or otheractions to perform this mixing step. However, it has been found that avery satisfactory mixim action can be obtained by pumping into thestream of oil, at right angles, a proportioned stream of the aqueousmedium.

The aqueous medium rthus added to the oil will be absorbed in whole orin part by the mucilagimucilaginous matter by the aqueous medium iscarried forward during fiow conditions. The temperature can bemaintained or increased by circulation of a medium, such as water,through the tank 24 by use of connections 25. In some instances, such acoil can be eliminated, particularly if the mucilaginous matter is of acharacter to absorb the aqueous medium to the desired degree quickly.

The treated oil discharged from the pipe coil 23 enters a mixer 26 whichmay be of a type similar to the mixer l8. Here, the refining reagent isadded to and mixed with the oil by any suitable means. As shown, therefining reagent is contained in a tank 21 equipped with a heating coil.This refining reagent is forced by a proport'ioning pump 28 through apipe 29 and into the mixer 28. If desired, a heater 30 may be interposedbetween the tank 21 and this pump.

It is preferable to correlate the pumping action of the pumps I5, 20 and28 so that properly proportioned streams are delivered to the system.

In the mixer 26, the refining reagent is intimately dispersed in andmixed with the treated oil and quickly neutralizes the fatty acids toproduce foots, in this instance largely soap stock. The resultingmixture is preferably conditioned for separation by the presence of anemulsionbreaking temperature which may be imparted in whole or in partby the preheating of the materials or by the expedient of applying heatto the oil-foots mixture before separation. A conditioning means 35 isshown in the latter capacity and can be used to perform other desirableconditioning functions otherthan merely heating, as will be hereinaftermentioned. In the embodiment shown, this conditioning means .includes apipe coil 36 positioned in a tank 31 through which a heating medium maybe circulated, if desired, through connection 38.

The resulting products are delivered through a pipe 39 to a separatingmeans 40, shown as comprising a high-speed centrifugal separator. Aconventional type of centrifuge may be used, providing a rotating bowldriven by a suitable high-speed motor or turbine, the centrifugal forceacting to throw outward the foots containing the soap stock and otherimpurities, these dilute aqueous solutions of other acids, such asacetic acid, sulphuric acid, etc. will often be foots then moving upwardin the bowl to discharge through a heavy eiiiuent spout 4|. refined oil,being of lower density, occupies a more central position in the bowl andis continuously discharged through a lighter efliuent spout 42. Ifdesired, this centrifuge may be of th heated-bowl type shown in myPatent No. 2,100,277, dated November 23, 1937. However, this expedientis usually not necessary though it can sometimes be used to advantage inbettering the action when processing certain oils. If used, the heatingmedium, such as steam, may be introduced to a position exterior of thebowl through a pipe 43 provided with a valve 44.

The refined oil may be further processed in any way known to the art.For instance, it may be washed and dried and subsequently treated withknown decolorizing agents. Similarly, the foots discharged from thespout 4| may be processed in known manners.

It will be noted that the system provides an elongated passage throughwhich the oil may move continuously. For instance, the oil may enterthis elongated passage as soon as it leaves the tank l0 and may bedischarged therefrom only when it enters the centrifuge 40. This flow ofoil is induced by the pump l5 which develops sumcient pressure to forcethe oil completely through the elongated passage and into thecentrifuge. During this flow in the elongated passage, the aqueousmedium and the refining reagent are added and mixed therewith insuccession. It has been found particularly desirable in a continuousprocess to utilize such an elongated passage closed from the atmospherein conjunction with separate proportioning pumps for forcing thereintothe oil, aqueous medium and refining reagent. V

The process will be found to work best if the following conditions andexplanatory principles are kept in mind:

The oil to be refined may be any of the animal or vegetable oils ormixtures thereof and will contain mucilaginous matter as well as otherimpurities which it is desired to remove, for example fatty acids andcolor impurities. The process will work particularly well on some oilsotherwise difiicult of refining, for example Brazilian or Egyptian crudecottonseed oils, though it will, in general, improve the refining of allvegetable and animal oils.

The aqueous medium may be any one of a number of liquids. Pure water hasbeen found to be very satisfactory. In some instances, an aqueous boricacid solution can be used, or very The found advantageous. Incorporationof a salt will often give desirable results. For instance, the aqueousmedium may contain sodium acetate, potassium acetate, sodium chloride,or other salts in dilute solution. In other instances, the aqueousmedium may comprise a solution imparting a tanning effect to the gums.

In general, this aqueous medium should be of such character that themucilaginous matter will have an affinity for it. In other words, theaqueous medium will be imbibed by the mucilaginous matter in such a waythat this mucilaginous matter will be impregnated therewith. Thisusually results in a swelling of the mucilaginous matter. Desirably, theaqueous medium should be of such character as to render the mucilaginousmatter repulsive to the refining reagent when subsequently added As tothe quantity of aqueous medium added, this will vary with differentoils. Usually, it is desirable that the aqueous medium be added inquantity as much as the mucilaginous matter therein will take up orimbibe, though beneficial results can sometimes be obtained by use ofsmaller quantities. In other instances, the aqueous medium can be addedin quantity greater than that which will be taken up by the mucilaginous-matter, thus producing additional advantages in the process, bothduring the conditioning step and the subsequent separation step. It willthus be apparent that no definite limits applicable to all oils can beset forth, for the quantity of aqueous medium utilized will depend uponthe quantity and the character of the mucilaginous matter present.Preliminary tests can be made on the oil to be refined to determine theoptimum quantity of the aqueous medium and the amount which will betaken up by the mucilaginous matter, though it can be said as a generalapproximation that the mucilaginous matter will usually imbibe aqueousmedium to an extent about equal to its own weight. Thus, with many oils,one or two per centof the aqueous medium will give desirable results,though even with these oils more may be used.

As to the refining reagent, any of the various reagents now known in theart for reacting with or associating with the impurities to form footscan be used. If the oil contains fatty acids which it is desired toremove, this reagent is preferably an aqueous alkaline solution of suchcharacter as to neutralize the fatty acids. The usual excess, or"slightly less, can desirably be used so as to combine color impuritieswith the foots to render them separable therewith and produce a desiredbleach of the resulting refined oil. Solutions of caustic soda, causticpotash, etc. have been found very effective. If acid refining, sometimesknown as partial refining, is desired, the refining reagent may be anyof those acidic materials known to the art as being useful in. this corknection.

If the refining reagent is added to the oil with- As a furtherconsequence, it issometimes possible. to use smaller excesses of therefining reagent than would be the case in an ordinary refining processin View of the fact that some of this refining reagent will not be takenup by the mucilaginous matter which has already imbibed the aqueousmedium to about its full extent.

There is usually a time element involved in the impregnation of the.mucilaginous matter by the aqueous medium. Thus, while an intimatemixture can be formed in the mixes", it is usually desirable to maintainthe mixture for a time sufilcient to effect substantially completeimpregnation. An excellent way of maintainin the aqueous mediumdispersed, as well as the par.-

tially or completely impregnated mucilaginous matter, is to move themixture through a conduit, for example the coil 23. In other instances,the mixture can be retained in the mixing zone for a longer period oftime and thus eliminate the coil 23 from the system. With some oils, themucilaginous matter will imbibe the aqueous medium with sufilcientrapidity to make possible the use of a short conduit in place of thecoil 23, even if the actual time in the mixer is quite short.

When the refining reagent is added to the mixer 26, it is intimatelydispersed in the pretreated oil and quickly becomes associated withimpurities. In the alkali refining of oils containing fatty acids, theneutralization is practiand the coloring matter or an absorption orcombining of the coloring matter with the foots. The

time required for this action will vary with different oils, dependingupon the color impuritics therein. On some oils, the necessary time willbe relatively short or even negligible, though on other oils, such asEgyptian or Brazilian crude mild turbulence due to flow through such apassage appears to effectively agglomerate these particles in such wayas to facilitate separation either continuously or in batches.

,Various expedients can be usedin separating the conditioned mixtureinto oil and foots. The addition of an aqueous medium to the oil isparticularly advantageous when separating centrifugally. Assuming firstthat the amount of aqueous-medium used has been only sufficient to meetthe demands of the mucilaginous matter, it will be clear that theresulting products entering the centrifuge will be composed in themainof refined oil'in' which is dispersed the swollen cottonseed oils,'theconditioning time in which the foots and excess alkali are dispersed inthe oil will be somewhat longer. The length of the chamber formed by theconditioning means may be varied to give the desired conditioning time.

elongated passage, or through a means which will .maintain theuniformity of the mixture, is desirable in this regard and will preventseparation of the foots or soap stock particles from the oil and delivera uniform mixture to the separating means. In addition, thisconditioning may involve a breaking of the emulsion formed by the stepof mixing the refining reagent if preheated materials are not used andif heat is applied during the conditioning step. Further, it may involvean agglomeration of the foots or soap stock particles in some instances,though not necessarily in all. Flow through an elongated passage, suchas is provided by the conditioning means shown, is very eflective inthis regard, for the .-mu cilaginous matter existing independently orcombined with dispersed particles of fonts with which are associated theabsorbed or reacted colorimpurities. When subjected to high centrifugalforce in a rotating bowl of-the centrifuge, all of those materials'whichare heavier than the refined oil will be thrown outward by centrifugalforce and will occupy a zone in the outer portion of the rotating bowl.The. centrifugal action is such as to squeeze from the swollenmucilaginous matter some of the water which, being heavier, assumes aposition immediately adjacent the wall of the rotating bowl. Such watercan become associated with the roots or soap stock to dilute same andthus efi'ecta very uniform discharge from the bowl. On theother hand, aportion of the water may form a layer along which the fonts or soapstock move upward, thus tending to prevent sticking of certainconstituents thereof to the wall of the bowl. In some continuousrefining processes as now practised, diificulty has been encounteredwith such sticking of some of the constituents to the bowl wall,resulting in an accumulation which 'prevents uniform discharge of thefoots and which shifts the neutral zone of the centrifuge. Without theapplication of heat to the exterior of the bowl, it has been found thatthe process must'be shut down every six or eight hours to permitcleaning of this accumulation from the bowl. In accordance with thepresent invention, the layer of water in the outermost portion of the 1bowl serves to prevent such adherence and facilitates continuousdischarge of the soap stock constituentaover long periods of timewithout shutdown. Even better action can sometimes be obtained bysupplementing this action with the application of heat to the exteriorof the bowl.

-If the amount of aqueous medium utilized is in excess of that whichwill be imbibed by the mucilaginous matter, this excess will usually bein the form of dispersed droplets and will be present during theconditioning and separating steps. When the refining reagent is added,the excess thereof will, to some extent, be diluted by thesedisperseddroplets of the aqueous medium and the diluted refining reagentwill not have as marked a tendency to react with the oil during thecolor-removing period as would be the case if no such dilution tookplace. If the excess of aqueous medium is slightly acid and an alkalirefining reagent is used, it will react with some of the excess refiningreagent and form a correspending salt. The excess of the refiningreagent increase the specific gravity or density of the soap stockconstituents, thus making for better separation, Such beneficial actionis particularly pronounced if the aqueous medium is used in excess ofthat required to swell the mucilaginous matter.

Use of such an excess of the aqueous medium is beneficial in thecentrifugal separation for the same reasons as set forth above, theexcess tending to form the layer of water in the outermost portion ofthe bowl.

Heat can beneficially be used in the process, being applied at one ormore points. In general, it can be said that an elevated temperaturesufiicient to facilitate separation is desirably present or appliedduring that step; also that an emulsion-breaking or opposing temperatureis desirably present or applied during this separation temperatures bothhigher and lower have been used with successpon some oils. Similartemperatures can be used in acid refining. Such a temperature may bepresent in the mixture entering the centrifuge as a result of heatapplied to one or more'of 'the materials before mixing or applied to theoil-foots mixture, or heat derived from both sources, following theteachings of Patents Nos. 2,100,274 and 2,100,275. On the other hand, itmay be the partial result of heat added adjacent the zone of centrifugalseparation, following the teachings of my patent supra and Patent No.2,100,276. Application of heat to the exterior of the rotating bowl ofthe centrifuge will, in general, raise the temperature of the heaviereliiuent much'more than the temperature of the refined oil. Forinstance, if heat is--thus applied and the temperature of the incomingconstituents is 140 F., the temperature of the heavier efiluent may be150 F. or more, and the temperature of the refined oil discharged willbe approximately 140 F.

In many instances, it is desirable to preheat one or more of theincoming materials. For instance, the incoming oil can often bepreheated to a temperature usually between about 120 F. and 160 F. anddesirably above 100 F. with advantageous results though, in otherinstances, the oil can be mixed with the aqueous medium and with therefining reagent at about room temperature and heat applied thereafter.If a preheating expedient is utilized, it will desirably be socontrolled as to maintain the resulting mixture at an emulsion-breakingor opposing temperature. This will additionally decrease refining lossesin preventing or quickly reversing the water-in-oil type of emulsionwhich commonly forms when the oil and refining reagent are mixed atsubstantially room temperature and which must later be broken orreversed by expedients such as the application of heat. Such preheatingwill often decrease the conditioning time, making it possible on someoils to substitute a short conduit for the coil 36.

If the incoming oil is preheated, it is usually, though not invariably,desirable to preheat the aqueous medium. Best results are obtained ifthe aqueous medium is heated to about the same degree as the oil though,in some instances, it is possible to pump the oil into the system atsubstantially room temperature and introduce the aqueous medium at anelevated temperature.

The use of a heated aqueous medium facilitates swelling of themucilaginous matter and the temperature of the oilnowing from the mixingmeans l8 will in this instance be somewhat above the temperature of theincoming oil, depending upon the temperature of the aqueous medium andthe proportion thereof utilized. a

If desired, the-refining reagent may also be preheated though this isnot essential in view of the fact that only small quantities of thisreagent are utilized.

Regard ess ofwhether the incoming materials are preheated,butparticularly if they are mixed at substantially room temperature,heat may be applied to maintain or raise the temperature of theoil-foots mixture during fio-w through the coil 36. Several of thefactors involved in the conditioning step are thus bettered oraccelerated, and, if desired, the mixture can be brought to thetemperature facilitating separation by heat applied at this point in theprocess.

In some instances, it is desirable to apply heat to the oil and itsimpregnated mucilaginous matter during flow through the pipe coil 23. Ifthe oil or the aqueous medium is introduced at substantially roomtemperature or with some degree of preheat, heat applied during flowthrough the coil 23 will facilitate impregnation of the mucilaginousmatter and will also be useful in the latter part of the process. Ifconstituents sufiiciently preheated are used, the temperature thereofcan be maintained during fiow through the coil 23 by circulation of asuitable heated medium through the tank 24.

It will thus be apparent that. the invention is not limited toheatapplied at any particular point in the system and that heat may beapplied at one or more of the points shown without departing from thespirit of this invention.

It will be understood that various materials can be added to the processin addition to those described. Such add tional materials may performother beneficial functions without materially changing the mode ofoperation herein defined. In some instances, such materials can bepumped into the system by use of the pumps shown, or they may beintroduced by auxiliary means.

While best results have been obtained by applioation of centrifugalforce to effect separation, the invention is not in all instanceslimited thereto. For instance, the resulting products discharged throughthe pipe 39 may be moved into various types of separating meansoperating either on the batch or continuous principle.

In other instances, it is not essential to continuously mix with the oilthe aqueous medium or the refining reagent, though best results havebeen obtained by such continuous introduction, particularly of therefining reagent. Thus, in some instances, it is possible to mix theaqueous medium with the oil before the mixture is pumped into the systemand even to add the refining reagent during batch mixing. Even then,however, it is desirable to separate the products centrifugally.

By the employment of the term aqueous medium or water," as used in theclaims, we mean to define and embrace either the employment of wateralone or such dilute aqueous solutions as to permit substantialhydration or impregnation of the gums or mucilaginous matter.

Various changes and modifications can be made in the process andapparatus without departing from the spirit of the invention as definedin the appended claims. I claim as my invention:

'1. A process of refining oils of the animal or vegetable typecontaining mucilaginous matter and other impurities, which processincludes the steps of: mixing with said oil an aqueous medium for whichsaid mucilaginous matter has an afiinity and which is capable of.impregnating said mucilaginous matter; then adding to and mixing withthe resulting product while the impregnatedmucilaginous matter remainsuniformly suspended therein a refining reagent capable of acting uponsaid impurities to form foot's; conditioning the resulting mixture ofoil and foots by flowing same through an elongated passage whilemaintaining such flow conditions therein as to prevent said foots fromseparating out of said oil; subjecting the conditioned products tocentrifugal action as fast as they issue from said elongated passage tocontinuously separate the oil from the remaining constituents of saidconditioned products; and maintaining such temperature conditions in theprocess as will deliver the conditioned products to the zone ofcentrifugal separation in non-emulsified condition. v

2. A process of refining oils of the animal or vegetable type containingmucilaginous matter and other impurities, which process includes thesteps of: adding to and mixing with said oil a quantity of water toimpregnate said mucilaginous matter; then adding to and mixing with theoil while said impregnated mucilaginous matter is uniformly suspendedtherein a refining reagent capable of acting upon said impurities toform particles of foots; subjecting the mixture to continuouscentrifugal separation while the same is in a condition facilitatingsuch separation, thereby to continously separate the refined oil fromsaid foots. I

3. A process of refining oils of the animal or vegetable type containingmucilaginous matter and other impurities, which process includes thesteps of: adding to and mixing with said oil a quantity of an aqueousmedium sufiicient to impregnate said mucilaginous matter; then adding toand mixing with the oil while said impregnated mucilaginous matter isuniformly suspended therein a refining reagent capable of acting uponsaid impurities to form suspended particles of foots; flowing theresulting oil and the suspended foots and impregnated mucilaginousmatter through an elongated passage at such rate as to maintain thefoots and mucilaginous matter uniformly associated with the oil;

and continuously centrifugally separating the refined oil from thefoots.

4. A process as defined in claim 1 in which said aqueous medium is addedin quantity greater than that which will be imbibed by said mucilaginousmatter whereby the excess present is dispersed in the oil atthe timesaid refining reagent is added and facilitates conditioning andcentrifugal separation.

5. A process as defined in claim 2 in which said water is added inquantity greater than that which can be imbibed by said mucilaginousmatter.

6. A process as defined in claim 1 in which said aqueous medium is addedwhile at an elevated temperature.

7. A process as defined in claim 1 in which said aqueous medium is addedwhile at an elevated temperature, and centrifugally separating saidconditioned products while at an elevated temperature well suited tothat step.

8. A process of refining oils of the animal or vegetable type containingmucilaginous matter and fatty acids, which process includes the stepsof: heating said oil; adding thereto while in heated condition anaqueous medium for which said mucilaginous matter has an afiinity andcapable of impregnating this mucilaginous matter; then adding to andmixing with the hot oil while said impregnated mucilaginous matter isuniformly suspended therein a refining reagent capable of neutralizingthe fatty acids to form particles of soap stock, while utilizing atleast in part the heat of said oil to produce an emulsion breaking oropposing temperature before ultimate separation of the oil from thematerials dispersed therein; and continuously centrifugally separatingthe resulting products into refined oil and a material containing saidmucilaginous matter and said soap stock.

9. A process of refining oils of the animal or vegetable type containingmucilaginous matter and fatty acids, which process includes the steps ofmixing with the oila small quantity of a hot aqueous medium for whichsaid mucilaginous matter has an affinity and capable of impregnatingthis mucilaginous matter; then adding to and mixing with the oil whilesaid impregnated mucilaginous matter is uniformly suspended therein analkali refining reagent capable of neutralizing the fatty acids to formparticles of foots and added in excess of that amount theoreticallyrequired for such neutralization; conditioning the resulting mixture ofoil, foots and excess refining reagent by flow througha conduit;subjecting the oil to an emulsionbreaking or opposing temperature beforethe time that it is ultimately separated from the foots; andcentrifugally separating the conditioned mixture while at an elevatedtemperature into oil and foot-s.

10. A process of refining oils of the animal or vegetable typecontaining mucilaginous matter and other impurities, which processincludes the steps of: introducing into a flowing stream of said oil andmixing therewith during said flow an aqueous medium for which saidmucilaginous matter has an afiinity'and capable of rendering saidmucilaginous matter repulsive to the action of a refining reagent;adding to the resulting stream a proportioned stream of a refiningreagent capable of acting upon'said impurities to produce a stream ofproducts including oil, dispersed foots and said mucilaginous matterimpregnated by said aqueous medium; subjecting the oil to an emulsionbreaking or opposingtemperature before the time that it is ultimatelyseparated from the foots; and continuously centrifugally separating saidoil from said products.

11. A process of continuously refining oils of the animal or vegetabletype containing mucit laginous matter and other impurities, whichprocess includes the steps of: introducing into a fiowlng stream of saidoil and mixing therewith during said flow an aqueous medium for whichsaid mucilaginous matter has an afiinity and capable of rendering saidmucilaginous matter repulsive to the action of a refining reagent;continuously adding to and mixing with the resulting stream aproportioned stream of a refining reagent capable of acting upon saidimpurities to produce foots and thus forming a stream of productsincluding oil, foots and said mucilaginous matter impregnated by saidaqueous medium; subjectmatter has an afiinity to impregnate thismucilaginous matter and form a stream of oil containing said impregnatedmucilaginous matter flowing along a subsequent portion of said passage;pumping into said subsequent portion of said elongated passage andmixing with said oil containing said impregnated mucilaginous matter arefining reagent capable of acting upon said impurities to form foots;discharging the products into a separating zone as fast as they movefrom said elongated passage; subjecting the oil to an emulsion breakingor opposing temperature before the time that it is ultimately separatedfrom the foots; and continuously centrifugally' separating refined oilfrom the products While in this zone.

13. A process as defined in claim 12 including the steps of applyingheat the material flowing therein.

14. A process of refining oils of the animal or vegetable typecontaining mucilaginous matter and fatty acids, which process includesthe steps of: pumping a stream of said oil along and completely throughan elongated passage; pumping into said elongated passage a stream of anaqueous medium for which said mucilaginous matter has an afiinity toimpregnate this mucilaginous matter and render it repulsive to an alkalirefining reagent, thus forming a stream of oil conheat to said passageto taining said impregnated mucilaginous matter flowing along asubsequent portion of said passage; pumping into said subsequent portionof said elongated passage and mixing with said oil containing saidimpregnated mucilaginous matter an alkali refining reagent capable ofneutralizing said fatty acids to form particles of foots; subjecting theresulting products as fast as produced to centrifugal action to separatethe refined oil therefrom; and applying heat to said elongated passageto produce an emulsion breaking or opposing temperature to discharge theresulting products into the zone of centrifugal separation while at atemperature facilitating this separation.

15. A process for refining oils of the animal or vegetable typecontaining mucilaginous matter and other impurities, which processincludes the steps of stream mixing with the oil an aqueous medium forwhich the mucilaginous matter has an aflinity and which is capable ofimpregnating said mucilaginous matter; then adding to and mixing withthe resulting product a refining reagent capable of combining with said.

impurities to form foots, the impregnation of said mucilaginous matterpreventing substantial taking up of said refining reagent by saidmucilaginous matter, developing such temperature prior to the ultimateseparation of the oil from its suspended materials as will cause the oilto be at an emulsion breaking or opposing temperature; and centrifugallyseparating from the oil a material comprising said foots and saidmucilaginous matter while using such amount of said aqueous medium inthe process that some of this medium will be squeezed out of saidmucilaginous matter during centrifugal separation to facilitatecontinuous discharge of the feats from the.

zone of centrifugal separation.

BENJAMIN CLAYTON.

